Hollow wall tray with corner lock



United States Patent 9 Inventors Charles E'. O'Connor Wakefield; Peter C. Collura, Waltham, Massachusetts Appl. No. 734,354 Filed June 4, 1968 Patented Nov. 10, 1970 Assignee Container Corporation of America Chicago, Illinois a corporation of Delaware HOLLOW WALL TRAY WITH CORNER LOCK 3 Claims, 6 Drawing Figs.

[1.8. CI 229/34 Int. Cl. 865d 5/22 Field of Search 229/34,

[56] References Cited UNITED STATES PATENTS 2,893,622 7/1959 Fogel 229/34(HW) 3,395,849 8/1968 Gelliam 229/34(HW) 3,450,347 6/1969 Lewisetjalz 229/34(HW) Primary Examiner-Joseph R: LeClair Assistant Examiner-Steven E. Lipman AttorneyRichard W. Carpenter ABSTRACT: A collapsible paperboard tray with the bottom panel and hollow side and end walls formed from a single blank. Each hollow end wall, near its ends, has a female lock opening. The stock released from the opening is left in to form a hinged locking tab. Each end of the inner panel of each side wall is formed with a male tab that enters the opening in the end wall when the tray is set up and is held between the edge of the opening and the adjacent edge of the hinged locking tab.

HOLLOW WALL TRAY WITII CORNER LOCK The principal objects of the invention are to facilitate the operation of setting up the hollow wall tray by providing a simple and effective locking means between the meeting ends of the walls at the tray corners which requires no particular skill or dexterity in bringing the locking parts together, and which will avoid inward bowing of the side walls and will improve the finished appearance of the tray due to an effective-squaring-up ofthe corners of the tray.

Other and more specific objects and advantages of the invention will become apparent as the description proceeds.

In the drawings:

FIG. 1 is a perspective view of the tray in setup condition;

FIG. 2 is a partial plan view on an enlarged scale showing the side portion of a form of blank from which the tray may be made;

FIG. 3 is a partial plan view on an enlarged scale showing an end portion of the assembled tray in collapsed condition;

FIG. 4 is a fragmentary detail view'on a still larger scale, showing the locking tab on the side wall inner panel;

FIG. 5 is a large scale detail view showing the construction of the locking opening in the panels forming the hollow end wall; and

FIG. 6 is a large scale sectional view, taken on line 6-6 of FIG. 1, showing how the hinged tab formed from the end wall panels engages the male locking tab on the side wall.

As herein disclosed the tray may be formed from a single blank of paperboard, cut and crease-scored to provide a rectangular bottom panel 1, which may be square or somewhat elongated, and to provide sets of attached panels at the ends and sides of the bottom to form hollow end walls and side walls. As the opposite groups of panels are identical, only one group of end wall forming panels and one group of side wall forming panels will be described in detail.

The end wall forming panels of each group are defined by fold lines 2, 3, 4 and 5. Fold line 2 separates outer wall panel 6 from the end of the bottom panel. Fold line 3 separates the outer wall panel 6 from top panel 7; fold line 4 separates top panel 7 from the inner upright wall panel 8; and fold line 5 separates panel 8 from the attaching panel 9 which in the manufacturing process is preferably folded through 180 relative to inner wall panel 8 and glued to the bottom panel at a location in which the panels 7 and 6 in the collapsed tray will lie flat against panels 8 and 9 and approximately in the plane of bottom panel 1.

The panels of each group which forms the hollow side walls are defined by fold lines 11, 12, 13 and 14. Fold line 11 separates the outer panel from the edge of the bottom panel. Fold line 12 separates outer panel 15 from top panel 16; fold line 13 separates top panel 16 from inner panel 17; and fold line 14 separates inner panel 17 from attaching panel 18 which, like panel 9, is preferably folded 180 and glued to the bottom panel at a location in which the panels 15 and 16 may lie flat against panels 17 and 18 in the collapsed condition of the tray. As indicated in FIG. 3, the end forming panels are folded inwardly at the ends of the bottom panel and the side forming panels are folded inwardly over the bottom panel and with their end portions overlying portions of the collapsed end wall panels.

For the purpose of securing together the end portions of the hollow walls, each end of the inner side wall panel is undercut sufficiently to provide a rigid tab 19 extending outwardly generally parallel to the fold line 13. The tab 19, which may be referred to as a male locking tab, is arranged to be secured within an opening 20 cut in the inner wall panel 8 of the hollow end wall. The opening provides a generally vertical free edge 21 which, as herein shown, is aligned with the inner side wall panel 17 and its tab 19 in the setup condition of the tray. When the hollow side wall is brought to upright position, the hollow end wall may then be swung up so that the male tab 19 is encompassed by the opening 20 and'the free edge 21 will move along the flat face of the tab 19.

The lower edge of the tab 19 is preferably cut on a curve as indicated at 22 so that such lower edge will engage frictionally against the edge ofthe material at the lower end of the opening 20. This is effected by spacing the lower end of the opening slightly farther from the bottom panel than the lower edge of tab 19. In other words, the distance of the edge 22 of the tab from the bottom panel is slightly less than the radius of the curved path described by the lower edge of the locking opening 20 as the end wall is moved to raised position.

In order to provide an additional retention or locking means, instead of completely removing the stock from the opening 20, this opening is cut to form a tab from such stock. This tab, indicated at 23 and referred to as a female locking tab, is preferably hinged along a fold line 23a at the lower end of the opening. The fold line 23a extends at a right angle to the free edge 21 along the side of the opening. The tab, as shown,

is formed by cutting the paperboard so that the edge of thetab, indicated at 24, is immediately adjacent the edge 21. By

this construction, when the hollow end wall is swung up, causing the opening 20 to encompass the tab 19, this tab will enter between the free edge 21 and the edge 24 of the female tab 23. In the setting up operation, the tab 23 will be swung'inwardly of the hollow end wall and, with the tab 19 in engaged position, the tab 23 tends to resist retrograde movement of the hollow end wall by reason of the cramping action exerted by the edge of the tab 23 op the rear face of the tab 19.

As herein shown, the opening 20 is extended across the fold line 4 and part way across the top panel 7, as indicated at 20a,

preferably tapering to a narrow end. A cooperating V-shapedcut or notch, indicated at 25, is made in the inner side wall panel 17 in alignment with the fold line 13 to define the upper edge of the tab 19. By this construction the material of the end wall top panel at the tapered end 20a of the opening enters the notch 25 and assists in providing a sturdy corner construction.

In the production of the blank, the scoring rules forming the fold lines 4,4 are preferably interrupted across the tabs 23,23 so that they will be left unscored. The tabs 23,23 remain in position within their openings in the collapsed condition of the tray, but when the hollow end wall is swung to upright position, the tab 23 is pushed inward by the entering end of tab 19, and the outer free end of the tab 23 will engage the under surface of the end wall top panel 7 and slide transversely along such under surface.

It is apparent that the hollow side wall is held in upright position both by the meshing engagement of the V-shaped notch 25 within the tapered end position 20a of the opening in the end wall top panel, and by the engagement of the hinged tab 23 against the rear face of the rigid tab 19. The retention effect of the hinged tab 23 on the tab 19 also tends to prevent retrograde movement of the raised hollow end wall, and this retention is reinforced by the frictional engagement of the lower edge 22 of the tab against the material at the lower edge of opening 20.

By the construction and arrangement above referred to, the hollow t'ray walls are initially locked in square condition and are so maintained. By the provision of the rigid tab on the inner side wall panel and by locking such tab securely in a definite locking position, the hollow side wall has no tendency to bow inwardly, thus assuring that the finished package will have a neat and attractive appearance.

References to side and end walls have been made herein solely for convenience of description, it being obvious that the hollow side walls disclosed can be made the same length or can be shorter than the end walls.

We claim:

1. A collapsible paperboard tray comprising:

a. a rectangular bottom panel;

b. hollow side and end walls attached thereto and being foldable upright, each of which walls comprises:

i. an outer panel hingedly joined to an edge of the bottom;

ii. a top panel hinged to the outer panel;

iii. an inner panel hinged to the top panel;

iv. an attaching panel hinged to the inner panel for connection to the bottom;

v. the inner panel of the hollow end wall being formed with an opening to provide a free edge substantially aligned with the inner panel of the hollow side wall when it is in final erected position;

vi. the end portion of the inner panel of the side wall being undercut to provide a male locking tab of restricted vertical width which may be received into the locking opening in the end wall inner panel with the face of the tab in contact with said free edge of the opening; and

vii. a female locking tab hinged on an edge of said end wall opening and being adapted to engage and hold said male tab between the edge of said female tab and the free edge of the opening.

2. A collapsible paperboard tray comprising:

a. a rectangular bottom panel;

b. hollow side and end walls attached thereto and being foldable upright, each of said walls comprising:

i. an outer panel hingedly joined to an edge of the bottom;

ii. atop panel hinged to the outer panel;

iii. an inner panel hinged to the top panel;

iv. an attaching panel hinged to the inner panel for convii. a female locking tab hinged on an edge of said end 7 wall opening other than the aligned free edge contacted by the face of the male tab, said hinged tab presenting an edge closely adjacent to said aligned free edge.

whereby said tab edge will engage the opposite face of the male tab at the end of the inner panel of the side wall and hold said male tab between the edge of the female tab and the free edge of the opening.

3. A tray as defined in claim 2 in which the female locking tab is hinged on a line at a right angle to the free edge of the opening in the inner end wall panel. 

